List of motorways in the United Kingdom

Roads which used to be motorways but have been downgraded:

The Adwick-le-Street to M62 stretch of the A1 is under consideration for upgrade to motorway standard, meaning the A1 between Blyth, south of Doncaster, to Birtley near Gateshead, would all be part of the same A1(M) stretch of motorway.

In addition, the proposal to put a tunnel under the River Thames to the east of Dartford Crossing and the revived Birmingham Western Orbital plans are both described as motorways.[39][40]

There have been many plans for motorways in the UK that have not been built. Below is a list of plans that were not built (not exhaustive):

• M1 Sterling Corner Link, linking the A1 at Sterling Corner to the M1.[41]
• M12 in 3 forms (although a small part was built and is not used - a stub sliproad):[42]
  • From the London end of the M11 to Brentwood;
  • From the London end of the M11 to Maplin Sands Airport (also not built);
  • From the M25 (in the vicinity of the M11) to Chelmsford.
• M13, from East London to Maplin Sands Airport passing south of Southend.[43]
• M17 Castle Donington bypass, a short spur off the M1. Now part of the A42.
• M19, M1 to A1 in Yorkshire. Functionally equivalent to the M62 between junction 29 and 32A, but located further to the north, and without the eastern extension to Hull.[44] Now part of the M62.
• M30, a proposed renumbering of the M3 once it was extended from Basingstoke to Southampton, but it never happened and the route remains the M3.[45]
• M31, a bypass of the busiest section of the M25, cutting the corner for traffic from the west.[46] Partially built as the A329(M) and A3290.
• M56-M62 Link, from the M56 to the M62, cutting the corner in Cheshire. Cancelled in 1993.[47]
• M58, very early proposed number for the proposed Preston Southern Bypass.
• M58 Mid-Lancashire Motorway, from west of Wigan to west of Bolton and the M61; cancelled in 1969. In the mid-1970s the M58 was reinstated, but as a two-lane dual carriageway and was cancelled again in 1986. In 1989, it was re-instated a second time, but was rerouted to end at the A58 instead of the M61 in 1993 and cancelled yet again in 1996. Wigan MBC picked up the M58 in the late 1990s, but only the western end was dual carriageway and the rest was downgraded to single carriageway. In 2007 the M58 was cancelled for good.[48]
• M59, M58 J2 to south of Preston. Gradually trimmed back and eventually cancelled, partially due to widening of the M6.[49]
• M60, a bypass of Altrincham and Sale, running from the M56 to Manchester. One section built as the A6144(M),[50] and the section between M6 and M56 was built as an all-purpose dual carriageway bypass of the A556.[51]
• M62 Relief Road, intended to relieve traffic on the existing M62, running alongside the M62 to the north and west of Salford and Manchester. Cancelled in 1995.[52]
• M64, between the M6 south of Stoke-on-Trent and the M1 near Derby. Cancelled in 1976 to save costs, but the central section was built as an upgrade of the A50.
• Most of the M67 – from Hattersley to the M1 via the Hope Valley in the Peak District national park and Sheffield. Various routes have been proposed but have yet to come to fruition due to controversy and/or expense.[53] In 2014, the then Sheffield Hallam MP and Deputy Prime Minister, Nick Clegg signalled his support for improvements to the Woodhead Pass.[54]
• M81, proposed number for the Maryhill Motorway and Trossachs Motorway, bypassing the A81 between Central Glasgow and Milngavie.
• M82, proposed number for the North Link Motorway and Lomond Motorway.
• M83, proposed number for the South Link Motorway and East Link Motorway, providing a south bypass of Glasgow via Rutherglen.
• M100, number reserved by the Department for Transport for a completed A1(M) between London and Tyneside.
• M111 (or M110), number reserved for the rump section of the M1 if the route was extended west to the A1. Because the M1 was extended east, the renumbering never happened.
• M272 Portswood Link, initially cancelled in the mid-1970s, but was reinstated in the 1980s as M27. Built as the A335 in 1989.
• M274, proposed number for the M27 spur / M275 mainline from the M27 northwards at Port Solent Interchange. Number never assigned or used; now part of the M27/M275.
• M601, which would have entered Manchester from the M62 (now the M60) in the Irwell Valley at Clifton near Pendlebury.[55]
• M650 Aire Valley Motorway, from near Silsden to Shipley. Cancelled in 1975; the A650 was built instead.[56]
• A2(M) Dover Radial Route, which would have run between Ringway 1 and Ringway 2. Built as the A2 Rochester Way Relief Road in 1988.[57]
• A6(M), bypassing Stockport to the west.
• A6(M) (or M66 extension), which would have formed an eastern bypass for Stockport.[58] As of March 2006, this is still under the planning stage as part of the SEMMMS (south east Manchester multi modal study) project (though not as motorway).
• A11(M), original number for the M11.
• A14(M), number for the planned upgrade of the A14 between Cambridge and Huntingdon. The proposal was dropped in 2019 to allow the road to be opened sooner, and it opened as the A14 as a "best in Class A road" instead.[59][60]
• A34(M), a motorway standard bypass of Handforth, Wilmslow and Alderley Edge. The route later opened as non-motorway A34 bypasses.
• A48(M) Llantrisant Radial, branching off the A48 and running west out of Cardiff towards M4 J33. Cancelled in 1971 in favor of construction of the M4 north of Cardiff.[61]
• A59(M) Ormskirk Bypass, planned bypass of Ormskirk, Burscough and Rufford. Became part of the planned M59 in 1963.[62]
• A61(M) Sheffield Urban Motorway Link[63]
• A556(M), which would have cut the corner between the M6 and M56 near Warrington, cancelled in 2003.[64] Completed in 2017 as an all-purpose dual carriageway bypass of the A556.
• A695(M) Shields Road Motorway, running from the A167(M) to A187 in Newcastle-upon-Tyne, cancelled in 1975. Later partially built as a bypass of the A193.
• A Ring, planned ring around Central London. Cancelled in 1950 as too expensive.[65]
• Belmont Link Motorway, linking the M6 to the A675 south of Higher Walton. It was proposed as part of the 1949 Road Plan for Lancashire, and its line confirmed by the Ministry in 1960, but no construction contracts were granted.[66]
• Bilston Link Motorway, linking M6 J10 to the A4123.[67]
• Blackpole - Whittington Motorway, proposed motorway in Worcester serving new development east of the city. The portion north of the B4636 is now the B4638.
• Central Motorway East Bypass, bypassing the Central Motorway East and the Tyne Bridge. Cancelled as it was ahead of its time, although some stub sliproads were built in case the motorway was built later.
• Central Motorway West, running from New Redheugh Bridge to Town Moor Interchange, cancelled in 1975. One section completed as the B1318 and another section became a surface-level road.
• Central Spine Motorway, running north-south via Worcester.
• Chippenham Spur, off the M4[68]
• Claremont Road Motorway, essentially an extension of the Central Motorway East to relieve traffic on Claremont Road. Built as the A167 and A167(M).
• Coventry North-South Motorway, running north to south through Coventry. All of the route (except for one section) built as the A444.[69]
• Cublington Airport Motorway, planned motorway to serve Cublington Airport.
• Denham Spur, cutting the corner between the M40 and Ringway 3 to the north
• Derby Urban Motorway, proposed link from the Derby Inner Ring Road (A601) to the then-A6 (now A5194) at London Road
• Droitwich - Leicester Motorway, a proposed pre-war motorway, one of two crossing the Midlands between the M1 and the Bristol-Birmingham-Preston motorway corridor (this one was southwest-northeast, the other was southeast-northwest). It eventually morphed into the M42 and M69 schemes. The route was numbered as M4 and M46.
• East Coast Motorway, unofficial proposal in early 1991 for a motorway running along the eastern side of England.
• East Cross Route, from Hackney Wick to Kidbrooke Park as the eastern section of Ringway 1. Now the A12 and A102.
• East Kilbride Motorway
• East-West Underground Motorway, running underground beneath Newcastle-upon-Tyne.[70]
• Eastern Motorway (Portsmouth), planned motorway running from the M27 to Portsmouth, complementing the M275.
• EuroRoute, rival proposal to the Channel Tunnel.[71]
• Friars Goose Crossing, planned crossing of the River Tyne, linking Newcastle to the south.[72]
• Furness Link, running from the M6 at Carnforth to Grange-over-Sands. Now the A601(M).[73]
• Glasgow Inner Ring Road, planned ring road around Glasgow city center. Partially built as M8 J15-J20.[74]
• Hamilton-Cumbernauld Motorway
• Hook Road, connecting Cardiff to the northern suburbs at the missing M4 J31. Cancelled in 1972 due to immense opposition.
• Johnstone Motorway
• Kendal Link
• Liverpool Inner Motorway
• London Oxford Airport Motorway
• Malvern Radial Motorway, proposed motorway in Worcester, running west of the city center and bypassing the A44 through St Johns and ending at the A4103 at Rushwick. A dual carriageway link would continue on to the A449 at Powick, taking traffic to Malvern.
• Manchester Inner Ring Road, planned ring road around Manchester city center.
• Morecambe Link Motorway, an east-west bypass of Lancaster
• Newport Southern Bypass, planned bypass of M4 to the south of Newport. Planned to be tolled, it was designated as M4 Toll. It was scrapped in 2009 due to increased costs of building the road. Although given full approval in 2014, it was cancelled again in 2019.
• North Cross Route, northern section of Ringway 1 (innermost ring of London). Only a small section was constructed at the eastern end, and no evidence has been found that it had a motorway number.
• Northern and Western Motorway, a 1923 motorway plan. A core section would run from the A45 to the east of Coventry, around southern Birmingham and the west of the Black Country and Wolverhampton north to Manchester and Salford and ending at the A57. A southern section would branch off at Coventry and head to London, paralleling the A41 and along the present A413 to the end of the proposed Western Avenue (A403) at the Denham Roundabout. A northern branch was planned from Altrincham to Liverpool and even a branch of this branch, from St Helens to Oldham, passing north of Manchester. Government disinterest and the power of the railways killed off the plan.
• Paisley - Hamilton Motorway
• Princess Parkway Motorway, heading south from Manchester. Part of route now the A5103 north of M56 J3.
• Ringway 2, planned upgrades of the A205 and A406 and a replacement for the Woolrich Ferry. One section, between the M11 and A13, would have been designated as the M15.
• Sheffield Spur Motorway, a section of M1 left over when it was rerouted to end at Doncaster. It was numbered M11 or M58 (depending on numbering scheme). This spur was extended towards Leeds and became the M1 again, while the rump bit between Thurcroft and Doncaster became the M18.
• South Bristol Spur, running from Ashton Gate to M5 J20. Portion of route now the A370.
• South Cross Route, the southern section of Ringway 1. Never built.
• Strensham – Solihull motorway, a link between the M50 and M42; it was routed via Evesham but this was cancelled as it ran through farmland, and so it was changed to ran through Redditch instead. In the earliest stages of planning, a route that would have linked it with the M69 was considered.[75]
• Thames Gateway Airport Access Road, linking M2 J1 at Strood to the proposed Thames Gateway Airport.
• Townhill Link Motorway, from M27 J6 (also not built) into Southampton via Townhill and ending at Mousehole Roundabout north of Bitterne. Unofficially numbered as M273.
• Trafford Park Motorway, sort spur with an intermediate junction that was part of SELNEC plans.
• Warndon Radial Motorway, proposed motorway in Worcester running from the Central Spine Motorway to the Blackpole-Whittington Motorway.
• Western Orbital Motorway - M6 north of M54/M6 junction to M5 near Bromsgrove. Planned to relieve congestion in the West Midlands, this would have diverted traffic heading north west to south west away from the heavily congested M6 south of Walsall. A spur was planned to link to the A449 north of Wombourne. This proposal has been around since construction of the M42 started. The idea hasn't been completely abandoned but is more likely to be built as an all-purpose road rather than a motorway.
• Weston Spur, running from the M5 to Weston-super-Mare

Many cities had urban motorway plans, most of which were not built. London,[76] Newcastle,[77] Liverpool,[78] Manchester/SELNEC and Glasgow[78] all had extensive plans.

The following motorways were planned, but never built

• M11, from the M1 going through Lisburn and then crossing the M1 again and ending at Newry[79]
• M23, from the M2 to Derry[79]

There were also urban motorway plans for Belfast.[80][79]